The invention relates to an axially-functioning grinding tool for fastening to a rotating shaft. The invention further relates to a material-processing machine, having a drive motor and a rotating shaft. The invention still further relates to the use of an axially-functioning grinding tool, and finally the invention relates to a method for processing a workpiece.
Grinding is a common process employed for treating the surface of a great variety of materials.
A distinction is basically made between three types of grinding processes, namely rotary grinding, oscillatory grinding and linear grinding. Certain combinations of the above mentioned three basic techniques also exist.
A grinding face, which performs a two-dimensional lateral grinding movement (oscillating movement) is often employed in oscillatory grinding. For example, an oscillatory grinder has a grinding face with a grinding device and oscillates in a straight and a circular manner.
Linear grinding is distinguished by a one-dimensional linear movement of the grinding device. A typical example is a so-called belt-grinder with rollers, which pull an endless grinding belt (for example a cloth grinding belt) over a stationary plate. The belt grinder exclusively grinds in one direction and is better suited for large surfaces than an oscillatory grinder.
In rotary grinding there is a rotary grinding body turning around at least one axis. Rotary grinding bodies, wherein a grinding device support of fleece or a fabric with elastic properties are used, are known. Such rotary grinding bodies are used in the treatment of wood (solid and veneer wood), for example, for surface treatments, such as finishing varnish grinding, or intermediate varnish grinding, as well as for smoothing, polishing and deburring of other materials.
For example, barrel-shaped grinding bodies of different diameters and length are used, wherein the grinding body, mounted on a support shaft, rotates. Such a barrel-shaped grinding body grinds in a radial direction with a linearly-extending engagement and abrasion effect. Because of low travel speeds, this attachment is of little interest for the industrial processing of materials. But more complex systems are employed in industry, some of which, however, are very elaborate, because they require several grinding rollers, which are partially obliquely placed and/or oscillate.
The commercially available grinding bodies mostly consist of ready-made abrasives embedded in plastic, textiles, wood or steel. The extensive and expensive storage of different sizes, hardnesses, types of action and abrasive grain sizes in respect to each other is disadvantageous to the user. The one-way use of these tools results in an unnecessary, in part considerable, increased consumption of support materials, along with a corresponding removal expense and the environmental strain and expenses connected therewith.
U.S. Pat. No. 4,625,466 describes a polishing tool with a belt-shaped polishing fabric, whose outer circumference is provided with abrasive grain. This belt-shaped polishing fabric is wound in a spiral shape on a tool disk. The polishing fabric is glued to this tool disk.
U.S. Pat. No. 1,417,593 discloses a further polishing tool. In this case a polishing device is spirally wound on it and fastened on a rotating disk by means of a clamping ring.
Another grinding tool is known from published European Patent Application EP 0 922 535 A1. The grinding tool is provided with radially arranged grinding plates. Radially arranged intermediate elastic elements are located between these grinding plates.
A further grinding tool can be found in German Letters Patent DE 24 11 749. With this tool, abrasive-coated paper in several bundles is arranged on the circumference of a rotating grinding disk. These bundles point radially outward. The service life of this tool can be extended by means of the bundling of several layers of abrasive-coated paper.
The object of the invention is based on producing tools and tool holders for processing workpieces.
It is a further object of the present invention to produce tools and tool holders which in particular make possible their being equipped in different ways in order to make possible the matching to the materials, surface shapes and surface conditions to be worked.
It is a still further object of the present invention to produce tools and tool holders which can be employed in connection with performance-oriented continuous production installations.
It is a yet further object of the present invention to produce tools and tool holders which, by means of the specific arrangement of a grinding device, perform the optimal cross-grinding effect with simultaneous working of rounded edges for varnish finishing or intermediate varnish finishing on surfaces with or without rounded edge ends, such as strips, profiles, window elements, etc.
The attainment of these objects is achieved in accordance with the invention by means of axially-functioning tools, a processing machine, and the use of the axially-functioning tools for workpiece processing in accordance with a preferred method for processing a workpiece.
The axially-functioning tool is adapted for being fastened to a rotating shaft and includes an inner and an outer rotating area. The inner rotating area includes a cylinder-shaped grinding device having several layers of a grinding device support which are arranged concentrically around the longitudinal axis of the rotating. shaft. The outer rotating area includes radially arranged strip-shaped grinding devices.
The material processing machine includes a drive motor and a rotating shaft operatively associated with the drive motor on which the axially-functioning tool is. attached.
The preferred method for processing the workpiece includes the steps of moving the workpiece in a linear direction and cross-grinding at least one surface of the workpiece by means of a multiple-layered cylindrical-shaped grinding device arranged concentrically around a rotating shaft. The method further includes edge grinding along at least one edge of the workpiece by means of strip-shaped grinding devices arranged in a radial direction in respect to the rotating shaft.
Advantageous further developments of the tools in accordance with the invention, the processing machine in accordance with the invention, the use in accordance with the invention and the method in accordance with the invention are defined in the dependent claims.
It is an advantage of the present invention that by equipping the tool holder in different ways, the tool can be adapted to the materials, surface shapes and surface conditions to be processed, and to the intended type of processing. Because of this, a cost-effective and flexible tool is available, which can be employed for the most varied purposes. It is a further advantage of the invention that commercially available grinding devices can be used for equipping the tool holder. This application can be performed in a simple manner by the user himself.
The tool in accordance with the invention can be used for simultaneous surface grinding, in particular for surface cross grinding (surface grinding with cross-grinding effects), and for grinding adjacent radii.
The tool can moreover be embodied in such a way that in connection with processing of wood it is also suitable as a high-performance tool for fine grinding up to varnish finish.
In other words: the tool in accordance with the invention is universal and offers a plurality of different employment options.
Further properties and advantages of the invention will be described in greater detail in what follows by means of the description and with reference to the drawings.